Karen Monahan, who Ellison said he was in a long-term relationship with which ended in 2016, came forward in August after her son posted on Facebook that he found a video on his mother's computer in 2017 that showed "Keith Ellison dragging my mama off the bed by her feet" and screaming profanities at her.

Ellison has denied the video exists.

Monahan also shared with 5 EYEWITNESS NEWS a health care record from Park Nicollet from November 2017.

Medical staff wrote, "She states that she was in a very stressful environment for years, emotional, and physical abuse by a partner with whom she is now separated. She did not have any physical injuries that required a physical examination in the past. She identifies the individual she was involved with as congressman Ellison, and she is worried about retribution if she identifies him publicly."

Monahan said on Twitter Wednesday that while she welcomed the investigation, she sees it simply as a way for Ellison - who is not seeking re-election to Congress - to try and diminish the impact of the allegations on his campaign for state attorney general.

"I am glad it will happen, but he is well aware he will be out of Congress before it is complete," she tweeted. "He makes himself look good before the election."

The Democratic-Farmer-Labor party has hired a private lawyer, Susan E. Ellingstad, to conduct their own investigation into the allegation.